FR2721985A1 - SHOCK ABSORBER FLYWHEEL INTENDED TO BE INTERPOSED IN A MOTOR VEHICLE DRIVE GROUP - Google Patents

Abstract

The invention provides a damping flywheel (10) of the type comprising a first (12) and a second (14) coaxial rotating elements generally in the form of parallel plates (20, 26), which define between them an annular housing (30) which receives an elastic damping device (32) and an annular space which receives a friction damping device (58), and of the type comprising two coaxial sealing washers (56A, 568). (58) comprises a part (62) driven in rotation by the second rotating element (14) via a head (68) of a member (66) for fixing one (56A) of the washers. sealing (56A, 568) on an annular disc (42) of the second rotating element (14).

Description

The present invention relates to a damped flywheel

  seur designed to be arranged between two sets of

  nants, one of which is connected to the internal combustion engine of a powertrain, in particular of a motor vehicle, and the other of which is connected to the input shaft

  of the transmission of this powertrain.

  The invention relates in particular to a damped flywheel

  type of the one described and represented in document FR-A-2 687 442 which comprises first and second coaxial rotating elements in the general form of parallel plates which define between them a sealed annular housing, delimited for the most part by the first rotating element arranged radially outwards, which receives an elastic damping device and a lubricating agent from this device, such as grease, and an annular space, arranged radially inwards, which receives at least

  a friction damping device.

  The elastic damping device acts circumferentially between the two rotating elements, while the friction damping device acts axially between the two rotating elements by being located at the level of the bearing, such as a ball bearing or a smooth bearing, interposed radially between the two rotating elements, usually consisting of masses, for their rotary mounting relative to each other. It is desirable to lubricate the various components of the elastic damping device and in particular the springs with their bearing areas and it has already been proposed for this purpose to delimit in a sealed manner the annular housing which receives the elastic damping device, and to separate it from the annular space which receives the friction damping device, so that it contains a lubricating agent which cannot penetrate radially inwards between the two rotating elements so as not to affect the proper functioning of the complementary friction damping device which is arranged in the annular space between the two rotating elements.

  In order to seal the housing, radial-

  Inwardly, it has already been proposed in document DE-U-79. 26142, sealing means which comprise two coaxial sealing washers, each of which bears by one of its faces against a first bearing surface associated with the first rotating element and by the other of its faces against a second

  bearing surface associated with the second rotating element.

  In the embodiment proposed in this document, each of the bearing surfaces is constituted by an annular O-ring arranged in an annular groove machined for this purpose in a portion of surface facing one or the other. of the two rotating elements and each washer is held radially by simple friction contact of its opposite faces with the

  two corresponding O-rings.

  The arrangement of the sealing means proposed in this document is particularly complex and costly in that it uses numerous components, in that it requires providing for the machining of grooves of precise dimensions for the O-rings of tightness and in that the assembly of the various components in order to ensure the correct positioning of the washers between their corresponding seals is particularly difficult to achieve

and to automate.

  In order to remedy these drawbacks, it has already been proposed in document FR 93 15571 filed on December 23, 1993 and not published to date, that each washer is mounted axially compressed between its two bearing surfaces and is capable of bearing radially. by one of its circular edges against a shoulder

  formed opposite on one of the two rotating elements.

  Such an arrangement is satisfactory, in particular in that it makes it possible to limit the radial size towards the inside of the sealing washers and allows the arrangement of two concentric friction damping devices, but the establishment washers and the assembly of the different components are not as easy as desired to make, the washers not being maintained in any way with respect to the different

  components until final assembly.

  The object of the present invention is to propose a damping flywheel of the type mentioned above, the structure of the sealing means of the annular housing being particularly simple and in particular making it possible to simplify the mounting of the washers and the assembly of the

different components.

  To this end, the invention provides a damping flywheel, characterized in that the friction damping device comprises a driven part

  in rotation by the second rotating element through-

  diary of at least one head of a member for fixing one of the sealing washers to an annular disc of the second rotating element, and in that said disc is fixed to the second rotating element by a series

  of connecting members separate from the fixing members.

  Thanks to the invention the disc of the second rotating element forms with its associated sealing washer a manipulable, transportable and captive assembly facilitating the reduction of the storage of parts and the mounting of the damping flywheel. This set also eliminates errors regarding the

sealing washer to be fitted.

  In addition, the sealing washer is provided because it is not fixed by the connecting members. In addition, the fixing member has, economically, a double function allowing to spare the fixing of the disc to

  benefit of great robustness of the damping flywheel.

  Advantageously, the second rotating element is hollowed out to avoid any interference with the feet of the

fasteners.

  Advantageously, the fixing members also make it possible to fix the second sealing washer to the disc of the second rotating element, said second sealing washer being pinched between the disc and the feet of the

fasteners.

  It is thus possible to manufacture separately a disc - sealing washer assembly and to assemble it

in the end without difficulty.

  According to other characteristics of the invention: - the second rotating element comprises an annular disc which extends inside the annular space and the annular housing and the opposite annular faces of which constitute said second bearing surfaces, l the fixing member being mounted on the annular disc; - The fixing member is simply and economically a rivet; this rivet has an enlarged head for driving the relevant part of the friction damping device; - An internal radial edge of said sealing washer is pinched between the head of the fixing member and the second bearing surface with which it cooperates; - The internal radial edge of said sealing washer is crossed by the body of the fixing member; - There is a series of fixing members for said sealing washer angularly distributed and whose heads rotate the second part of the friction damping device; the annular disc is fixed to the second rotating element in the form of a plate by a series of connecting members distributed angularly; - The connecting members and the fixing members are arranged substantially on the same circle while being distinct; - the other of the two sealing washers can be fixed on the second rotating element; - The internal radial edge of said other sealing washer is pinched between the annular disc and a bearing surface formed on the second rotating element;

  - the connecting members are rivets.

  Other characteristics and advantages of the invention

  tion will appear on reading the detailed description

  which will follow for the understanding of which reference will be made to the appended drawings in which: - Figure 1 is a view in axial section along line 1-1 of Figure 3 of an exemplary embodiment of a damping flywheel in accordance with teachings of the invention; - Figure 2 is an enlarged view of detail A of Figure 1; and - Figure 3 is a partial right view, partially illustrated in section along line 3-3 of Figure 1 of the damping flywheel illustrated in this figure. There is shown in Figures 1 to 3 a damping flywheel 10 which is essentially constituted by a first rotating element 12 and a second rotating element 14, which are capable of rotating one relative to

the other around an X-X axis.

  The rotating elements 12, 14 here consist, in a manner known per se, of coaxial masses mounted mobile relative to each other against an elastic damping device 32 with circumferential action and a damping device to

friction 58 with axial action.

  The first element 12, here in the general form of a plate, comprises an external toothed ring 16 intended to cooperate with a starter of a powertrain (not shown) and a central hub 18, produced in one piece with the plate 12, provided to be fixed on

  the end of an engine crankshaft (not shown).

  The rotating element 12 is essentially constituted

  tiel by a plate 20 and by a peripheral annular skirt

  cylindrical rique 22, of axial orientation, which partially surrounds a cylindrical peripheral annular skirt 24, which extends axially the main plate-shaped part 26 of the rotating element 14, which is rotatably mounted on the hub 18 via here a ball bearing 28 or alternatively by another bearing

for example of the plain bearing type.

  Trays 20, 26 and skirts 22 and 24 delimit

  tent an annular housing 30 which is designed to receive, according to a known design, the elastic damping device 32 consisting of a set of springs

  helical, here concentric, arranged in a crown.

  This housing 30 is here largely defined by the plate 20, the skirt 22 and a disc 34 of the first

rotating element 12.

  At its internal periphery, this housing reveals a slight slot in which a disc 42 of the second rotating element 14 penetrates, and this with sealing

as described below.

  The first rotating element 12 also includes the internal radial disc 34 which extends radially inwards from the skirt 22 between the two plates, 26 in the direction of an annular space 36 delimited between the portions of planar faces facing each other. -vis 38 and 40 of

plates 20 and 26.

  The disc 34 is linked in rotation to the outer skirt.

  lower 22 by sealed crimping as described in document FR-A-2 695 579. To do this, the skirt has a groove intended to receive the metal from the metal disc 34, during the forging of the latter. As a variant, this waterproof attachment can be produced by screwing as described in document FR-A-2 687 442. Alternatively, riveting or welding can be carried out. This disc 34 partially defines the housing 30, the plate 26 being hollowed out for housing the disc 34, which is locally stamped at 80, as visible in FIG. 1, for support of the circumferential ends of the helical springs of the device 32. Opposite of these pressed 80 the plate 20 has plates 81 fixed by riveting (as visible in the lower part of Figure 1) for support

  circumferential ends of said springs.

  The second rotating element 14 also comprises an internal disc 42 which is linked to it in rotation by rivets 44, and which extends radially in space

  annular 36 and in the annular housing 30.

  The second rotating element 14 forms, using its plate 26, in a manner known per se, the reaction plate of a clutch. Thus, this second element 14 is intended to be locked in rotation on the input shaft of the gearbox by means of a clutch friction disc, the friction linings of which are intended to be pinched between the reaction plate 26 and a pressure plate, not shown, belonging to a clutch mechanism intended by its cover to be attached by screws, one of which is visible in the

  upper part of FIG. 1 on the reaction plate 26.

  The outer edge 46 of the inner disc 42 has outer radial lugs 50 provided to serve as stops at the ends of the springs of the device

cushioning elastic 32.

  Thus the springs, bearing on the plates 81 and the stamps 82 of the disc 34, here by means of support studs 83 in a manner known per se, are intended to be compressed by the lugs 50 penetrating into the housing 30. Note that anti-wear parts 82, here in the form of a chute, are interposed

  radially between the springs 32 and the skirt 22.

  The peripheral part of the disc 42 extends between a portion of surface facing 52 of the plate 20 and a portion of surface facing 54 of the radial disc

  internal 34 of the rotating element 12.

  Thus the legs 50 penetrate inside the housing 30, a small gap existing between the

  plate 20 and the disc 34 for penetration of the disc 42.

  The internal sealing of the annular housing 30, and its separation from the annular space 36, is ensured by

  two sealing washers 56A and 56B.

  The two washers 56A and 56B are two annular pieces of cut and stamped sheet metal and therefore close the housing 30 at its internal periphery, said housing being partially filled with grease to lubricate the

device springs 32.

  As can be seen in Figure 2, the outer radial edge of the washer 56A cooperates and is in elastic abutment against a bearing surface formed opposite in the plate 20 of the first rotating element 12, while the edge external radial of the second sealing washer 56B cooperates and is in elastic abutment against a bearing surface formed opposite

  on the disc 34 of the first rotating element 12.

  The washers 56A and 56B are arranged according to the invention on either side of the disc 42 while being

attached to it.

  The damping flywheel 10 also includes a friction damping device 58, of known structure. This device 58 surrounds the hub 13 and comprises a first part 60 constituted by a ring of friction material, which is intended to rub on a portion of the planar surface 38 of the plate 20 of the first element 12, and by a second part 62 which is constituted by a washer, here metallic, driven in rotation, possibly after taking up a clearance, by the second rotating element 14. An elastic washer 64, which resiliently urges the washer 62 to bear against

  the friction ring 60 is also provided.

  The washer 64, of the Belleville washer type, as a variant a washer of the wavy washer type, is supported on a ring axially wedged on the internal ring of the bearing 28 mounted on the hub 18. This hub 18 is provided with through holes for screws fixing the flywheel to the engine crankshaft. Such a screw is

  visible in the central part of figure 1.

  Thus the flywheel is arranged between two rotating assemblies, one of which (the crankshaft) is connected to the internal combustion engine and the other of which is connected to the shaft.

gearbox input.

  The ring 60 is fixed to the washer 62 here by gluing. Thus the ring 60 is intended to be clamped axially between the washer 62, forming a washer of

  distribution, and the portion of the surface 38.

  In accordance with the teachings of the invention, the washer 62 is rotated by the heads 68 of a series of rivets 66, which are fixed to the disc

  inner annular 42 of the second rotating element 14.

  According to the invention, and as can be seen in FIG. 2, the internal radial edge 70 of the sealing washer 56A is pinched between the head 68 of

  each rivet 66 and the flat surface portion opposite

  screw of the annular disc 42 of the second rotating element 14.

  Thus according to the invention the first washer

  seal is fixed on the disc 42.

  For this purpose, the internal radial edge 70 also includes a series of corresponding holes through which

the bodies of the rivets 66.

  This arrangement allows, in addition to the rotation drive of the washer 62, to secure the sealing washer 56A on the annular disc 42, and therefore on the second rotating element 14, the cooperation of the internal radial edge of the washer 56A with a bearing surface arranged opposite to the annular disc 42

  sealing the annular housing 30.

  This design ensures the mounting and fixing of the sealing washer 56A on the annular disc 42 of the second rotating element 14 before the fixing of the annular disc 42 on the plate 26 of the second rotating element 14 by means of the series of rivets

liaison 44.

  Advantageously according to the invention, these rivets 44, distinct from the rivets 66, only ensure the fixing of the disc 42 without ensuring the fixing of the washer.

  seal 56A, which is thus provided.

  Advantageously, the second sealing washer 56B is fixed in the same way as the washer 56A to

using the fasteners 66.

  Thus the internal radial edge 72 of the washer 56B is pinched between the foot of each rivet 66 and the portion

facing disc 42.

  This internal radial edge 72 has holes

  crossed by the bodies of the rivets 66.

  Thus the radial edges of the sealing washers 56A, 56B extend in contact with the disc 42 on either side of the latter, the assembly forming an assembly

  easy to handle, transportable and captive.

  As can be seen in FIG. 3, the fixing rivets 66 and the connecting rivets 44 are advantageously arranged substantially on the same circle and

  alternated regularly along this circle.

  In the embodiment illustrated in the figures, the internal radial edge 72 of the sealing washer 56B cooperates in sealed manner, by elastic support, with a bearing surface formed opposite on the annular disc 42 of the second rotating element 14

  thus ensuring the tightness of the housing 30.

  According to an alternative embodiment which is not shown in the figures, it is possible to provide that the sealing washer 56B is also fixed to the second rotating element 14 by pinching its inner radial edge 72 between the inner annular disc 42 and the portion of facing plane surface 40 formed on the

tray 26.

  Note that the second rotating element 14 has recesses opposite the feet of the rivets 66 to allow the passage of said feet, the disc 42 allowing the setting of the outer ring of the bearing 28 between a shoulder of the second element 14 and the periphery

  disc 42 internally perforated centrally.

  Thus for the record it will be recalled that, during the operation of the damping flywheel, the springs of the device 32 are allowed to be compressed between the arms, the plates 81 of the plate 20 and the stampings 80 of the disc 34 of the first rotating element 12. this movement, the head 68 of the rivets rotates the washer 62, which drives the washer 60 with

  appearance of friction in contact with the surface 38.

  Of course, the present invention is not limited to the embodiment described. In particular, the washer 62 could, as disclosed in the document FR-A-2 687 442, be linked in rotation to the hub 18 by an assembly of the spline type, said washer 62 then having at its internal periphery teeth engaged, possibly with play, in grooves

  formed at the outer periphery of the hub 18.

  As a variant, the setting in rotation of the washer 62 on the hub 18 could be carried out using flats. The washer 60 would then have at its outer periphery notches for penetration of the heads 68 of the rivets and driving in rotation of the washer 60, possibly after taking up a clearance, by the second rotating element. This is made possible by the shape of the head 68, which is relatively long by being shaped

of pawn.

  Similarly in Figure 1, we can stick the washer on the plate 20 and not on the washer 62. A

  friction then occurs between the washers 60,62.

  Of course you can mount the washer freely

  between the plate 20 and the washer 62.

  The shape of the washers 56A, 56B can be different knowing that said washers are here intended to be fixed preferably at their internal periphery on the disc 42 using rivets 66, while by their external periphery they are intended to come in support respectively on the plate 20 and on a span

  formed at the internal periphery of the disc 34.

  By their external radial edge these washers 56A, 56B are therefore in abutment against a first bearing surface associated with the first rotating element. By their inclined radial edge these washers 56A, 56B are in abutment against a second bearing surface offered by the disc 42

  associated with the second rotating element 14.

  It will be noted that in the figures the internal periphery of the washers 56A, 56B is offset axially by

  relative to the outer periphery of said washers.

  A clearance exists between the disc 42 and the outer periphery of the sealing washers. Of course the number of rivets 66 depends on the applications. Preferably several rivets 66 are used.

Claims (10)

  1. Damper flywheel (10) arranged between two coaxial rotary assemblies (12,14) one of which is intended to be connected to the internal combustion engine of a powertrain, in particular of a motor vehicle, and the other of which is intended to be connected to the input shaft of the gearbox of this powertrain, of the type comprising a first (12) and a second (14) coaxial rotating elements in the general form of parallel plates (20, 26) which define between them an annular housing (30), delimited for the most part by the first rotating element (12) and arranged radially outwards, which receives an elastic damping device (32) with circumferential action and a lubricating agent of this device (32), and an annular space (36), arranged radially inwards, which receives a friction damping device (58) with axial action, and of the type comprising sealing means which separate the   housing (30) and space (36) annular and which comprises   tent two sealing washers (56A, 56B) coaxial, each of which is supported by one of its faces against a first bearing surface associated with the first rotating element (12) and by the other of its faces against a second bearing surface associated with the second rotating element (14), in which the second rotating element (14) comprises an annular disc (42) which extends inside the annular space (36) and which penetrates by its periphery external in the annular housing (30), characterized in that the friction damping device (58) comprises a part (62, 60) driven in rotation by the second rotating element (14) by means of at least a head (68) of a member (66) for fixing one (56A) of the sealing washers (56A, 56B) on the annular disc (42) of the second rotating element (14), and in that the annular disc (42) of the second rotating element (14) is fixed to said second element (14) by a series liaison bodies (44)   separate from the fasteners (66).   2. damping flywheel according to claim 1, characterized in that the opposite annular faces of the annular plate (42) constitute said second bearing surfaces, and in that the fixing member (66)   is mounted on the annular disc (42).   3. damping flywheel according to claim 2, characterized in that the fixing member (66) is a rivet.   4. Damper flywheel according to one of the claims   cations 2 or 3, characterized in that the internal radial edge (70) of said sealing washer (56A) is pinched between the head of the fixing member (66) and the   second bearing surface with which it cooperates.   5. Damper flywheel according to any one of   Claims 2 to 4, characterized in that the radial edge   internal (70) of said sealing washer (56A) is   crossed by the body of the fixing member (66).   6. Damper flywheel according to any one of   previous claims, characterized in that it is   provided a series of members (66) for fixing said sealing washer (56A) angularly distributed and whose heads (68) rotate the part (62) of the   friction damping device (58).   7. Damper flywheel according to any one of   previous claims, wherein the washers   sealing rings (56A, 56B) are arranged on either side of the annular disc (42) of the second rotating element (14), characterized in that the second sealing washer (56B) is fixed to the annular disc ( 42) of the second rotating element (14) using the fixing members (68), the internal radial edge (72) of said sealing washer (56B) being pinched between the base of the fixing members (66) and the second bearing surface with which it cooperates with.   8. Flywheel damper according to claim 6 or 7, characterized in that the annular disc (62) is fixed to the second rotating element (14, 26) in the form of a plate by a series of connecting members (44) angularly distributed. 9. damping flywheel according to claim 8, characterized in that the connecting members (44) and the fixing members (66) are arranged substantially on a same circle.   10. Flywheel damper according to claim 8 or 9, characterized in that the connecting members (44) are rivets.